In the area of cosmetic emulsions for skincare and hair care, a large number of requirements are imposed by the consumer: apart from the cleaning and care effects, which determine the intended use, value is placed on such differing parameters as highest possible dermatological compatibility, good refatting properties, elegant appearance, optimum sensory impression and storage stability.
Besides a series of surface-active substances, preparations which are used for the cleaning and care of the human skin and the hair generally comprise in particular oil bodies and water. The oil bodies/emollients used are, for example, hydrocarbons, ester oils, and vegetable and animal oils/fats/waxes. In order to meet the high market requirements with regard to sensory properties and optimum dermatological compatibility, new oil bodies and emulsifier mixtures are continuously being developed and tested. The use of ester oils in cosmetics has been known for a long time. On account of their importance, new processes for their preparation are also continuously being developed. In particular branched ester oils impart a “lighter” skin feel and are therefore being intensively investigated. The use of 2-methyl-1,3-propanediol monoesters is, for example, the subject of DE 101 60 681, the use of 2-methyl-1,3-propanediol esters is described in DE 101 60 682.
It was an object of the present invention to provide novel ester oils that are preferably liquid at 20° C. for cosmetic applications which have an improved profile with regard to the sensory properties (lightness, “nongreasy skin feel”, softness, spreadability, absorption, distributability, oiliness) and can be incorporated into a large number of cosmetic formulations. In this connection, the hydrolysis stability of the esters and also the ability of the esters to be formulated at a low pH were also of interest. Furthermore, it should be possible to incorporate the esters both into W/O and also into O/W formulations. Furthermore, the esters should be compatible in particular with crystalline UV filters, pigments, antiperspirants salts and silicones. Surprisingly, it has been found that esters of 2-ethylbutanol lead to sensorily light products. Some of these esters are described by Wu, Y. et al., Huaxue Tongbao, 1985, (5), 19-24. Kano, T. et al. (2005) Jpn. Kokal Tokyo Koho (2005), 15 pp describe the use as environmentally friendly solvent for cleaning.